Method



J. .1.. `KoETz v1,941,557 METHOD FOR PREPARING4 cATALYsTs Filed March 5, 1930 l HERHacoz/PL:

JCI/Mmes L. Koefz INVENTOR ATTORNEY vacated Jaa 2,1934

1.941.551 A IMETHQD, FOR PBEPARI G CATALYSTS Johannes L. Koetz, Pittsburgh, Pa., vassigner to The Selden Company, Pittsburgh, Pa., a corl poration of Delaware sppucstiomnmch 5, 1930. serial No. 433,477

'15 Claims.

This invention relates' to a method and apparatus for preparing catalytic material, and more particularly for the pretreatment and calcination that is necessary for many catalysts 5 before they are in condition for commercial use .and for the regeneration of such catalysts after use. -Objectsof the invention are to provide an apparatus and a method of treatment that will result in an even and uniform heating of the raw l or spent catalytic material and an even heat distribution therein together with a regular and even cooling of the material after the heat treatment has been completed.

The invention is applicable in general to Aall l types of catalytic material, but its greatest utility will probably be found in the treatment of oxidation catalysts which are usually prepared in the form ofv pellets which must be submitted to a preliminary treatment with hot gases, and particularly to complex catalysts which contain water of hydration such as permutogenetic catalysts and the like.. These substances are originalLv prepared in the form of wet hydrated gels, which upon drying at temperatures preferably 26 below 100 C. are transformed into porous honeycomb like solids containing water of hydration. They may be properly described as raw catalysts. In this stage they exert catalytic properties, but it is necessary-to neutralize alkalinity and to 30 remove the water of hydration in order to attain full activity and uniform conversion, and this -is usually done by subjecting the catalytic material to a calcination with acid gases, a mixture of sulfur. dioxide and air followed yby a cooling treatment with air alone being preferably used. Such catalysts are described, for example, in Patent. Nos. 1,657,754 to Alphons O. Jaeger et al. and 1,675,308, 1,675,309, 1,694,123 and 1,709,853 to Alphons O. Jaeger. The iirst four of these patents describe catalysts for the contact sulfuric acid process, and the last patentA describes catalysts for the catalytic oxidation of organic material. l

In accordance with the presentinvention, the previously dried but not entirely dehydrated catalytic material is dehydrated in a continuous stream by subjecting earlier portions of the stream to the action of acid gases and air preheated to reaction temperatures or higher at the start of the process and the latter portions of the stream to a blast of coolingl gas. When the chemical reaction has once set in the initial preheating may be reduced or dispensed with, depending on the amount of heat given off by the reaction.

The inventionwill be more, particularly `described in connection with the accompanying drawing which shows certain examples ofmeans for effecting the process andthe treatment of the catalyst with sulfur dioxide and air, as this is a preferred modification, but it isito be understood that the said drawing is illustrative only and the invention is not limited thereto;

Fig. 1 is a vertical section of a complete continuous calciner with a continuous discharging 66 mechanism. l

Fig. 2 shows a modified discharge mechanism therefor. Fig. 3 is a detail of one of the discharging elements.

Referring to Fig. l, the calciner consists of air outer shellrl, to which is aiiixed charging means 2, consisting of duplicate hoppers 3 and 4 with separate feeding mechanisms 5 and 6 respectively and separately removable covers 7 and 8. One or more pipes 9 and 10 are provided for the admission of reaction gases and fresh air, these pipes entering the shell 1 near its upper and low- 4only and that in larger installations or the spparatus a plurality of these umts will be used. 90

.In such installations the baille 15, which is shown as being placed over the upper tube to prevent its filling with catalyst will be duplicated for each additional unit. A well 16 is provided, in

which suitable thermocouples 17 or other tem-v perature indicating devices may be placed which may be so connected with the valve 18 and 19 in the pipes 9 and 10 as to provide automatic control -for the apparatus.

In operation a continuous stream of the catalytic material to be dehydrated which may be, for example, a diluted non-siliceous base exchange body containing vanadium is by the alternate action of the charging means 5 and 6, the hoppers?. and 8 being nlled alternately in such a manner that continuous action is maintained. The catalytic material passes downwardly over the baille 15 and around the closed end tubes 13 and 14 and is discharged by a continuous discharging mechanism 20, the op- 110 eratlon-ofwhichispresentlytobedescrlbed. Hot gasesy containing sulfur dioxide and air, preheated to reaction temperatures, areadmitted throughthepipesandpassdownwardly through the pipe 1l, reverse their new and pass upwardly thepipe 13, and again reverse their flow .under the lniiuence of the bame 15 and pass downwardly through the descending catalytic material and exit through the pipe 21. Simultaneouslywiththistreatmentairisadmitted from a blower (not shown) through the pipe and; passesin'the same manner as the sulfur dioxide gases through the concentric pipes l1 2 and I4, first in indirect and then in direct heat exrelation with the calcined catalytic material'and finally passes upwardly through the material counter to its downward now and exits through the pipe 21. Y

From` this construction it will be seen that by applying the principles of the present invention a very effective and complete calcination and cooling of the catalytic material can be eilected in a continuous stream without danger of sintering the material or the apparatus by overheating. The calcination' of such material isin'eil'ectanoxldationofthesulfurdioxide gases to sulfur trlexide, using a continuous streamefi'reshcatalystand discharginglthat which has been treated, and the problem of controlling the rate of heat evolution of the reaction iirpresentjustssinthecommercialproductionl thehotzonetotheuppersoneswhereitisneeded. mthesametheeoolingairadmit- 'tedthe'pipeioemertsastrongeooling 'action ou the catalyst at the het central sone opemendtubellis-gradually heated sothat it isinemeelies'iteenditiontosweepallthelastretueeaotwatennxlfurtrloxidaandany sulfurdioxidefromthecalcinedcat- Incaaeswheretheprinciples of theinvention aseic-beappliedtctheregenerationotspent eatalyticmateriahforexampleinprocessessuch asthme described in the Jaeger Patents 1,678,626 andMJheremayormaynotbqane wlthinthecatalytic material itselfdepmdingenthenatmeoitheimpm'lties "Ti absesbedby. thecatalyst and of the www distributed by the heat exchangers, and pass catalysts, and many important y In the specification the tes-m1 gases. In all vsuch cases where insumcient heat is generated it may b e supplied by suitably preheating the acid or halogen gases which are admitted through the pipe 9, the heat being evenly through the moving stream of catalyst as does the sulfur dioxide and air in the method'that has been described. The ilow of cooling air under such conditions .usually remains the same.

The discharge mechanism'may be of any suitable type, but'it is preferable to use one which will effect a continuous and uniform discharge at a predetermined rate and one which will not permit the escape of objectionable fumes from the apparatus. A representative mechanism has been shown in connection with'lllg. l. which consists of a revolving member 21 provided with cylindrical oriiices 22 of predetermined capacity, the whole rotating on a shaft 24 and surrounded by a suitable casing 23. Thev lower end of the shell 1 is constricted to form an outlet passage 25 across which extends a gate 26 which is designed to operate'slidably in bearings 27 and to be actuated by a crank p in or other similar means mounted on the shaft 2 4, or connected thereto by 100 suitable gearing if desired. In operation the opening of the gate,2 6 allows a predetermined amountof the calcined material to be discharged into. the cylindrical openings of the rotary member 21,'from which it falls by gravity onto the 105 conveyor belt 28 and is conducted to storage or elsewhere. y 1' 5 A discharge mechanism design to give a more accurate and uniform measurement of the discharged catalytic material is shown in Fig. 2 and 110 consists of' an inclined rotary drum 30 provided with openings 31 and 32 mounted in a surrounding sleeve 33 and driven by a suitable shaft and gearing 34. The discharge. sate 26 is driven by a suitable cam and rocker arm 35 mounted on the 115 shaft 34 and operates in synchronism therewith to permit the discharge of measured amounts of the catalytic material into the drum 30 when the opening 31 comes into registry withthe lower portion 25 of the calciner shell. Upon rotation of the 120 'shaft .34 through 180 the catalytic material is discharged onto the conveyor belt 28 through the opening 32, at which time the gate 28 is closed and the intake 31 of the cylinder is out -of registry with the discharge 25. A measured amount ofthecatalytiematerialisthusallowed mentasthlsisthepreferred istobeunderstoodhoweveathatthe isnotlimitedtotheuleofacidganesertogases whicharereactiveortoanyparticnlarclanot advantages obtainedevenwhennon-reaetivegaxeused;

wnscacmmeaumu:

2. A process of treating raw catalytic material which comprises maintaining a ilow of said material and passing longitudinally of said flow a gaseous mixture heated to reaction temperatures and capable of setting up an exothermic reaction .in the presence of said catalytic material and thereby driving off moisture.

3. A process of treating raw catalytic material, which comprises maintaining a flow of said material and passing through said material in the direction of' its flow a gaseous mixture heated to reaction temperatures and capable of setting up an exothermic reaction in the presence of said catalytic material and thereby driving off moisture.

4. A process of treating raw catalytic material, which comprises maintaining a flow of said ma-v terial and passing through said material in the direction of its ilow a gaseous mixture heated to reaction temperatures and capable of setting up an exothermic reaction in the presence of said catalytic material and thereby driving off moisture and subjecting further portions of the iiow of material to heat exchange with a stream of cooling gas.

5. A process of treating raw catalytic material which comprises maintaining a ilow of said raw material containing water of hydration in con-A tact with at least one heat exchanger and passing a heating fluid through said heat exchanger and then through said catalytic material.

6. A process of treating raw catalytic material, which comprises maintaining a flow of said material througha reaction chamber, introducing a mixture containing acid gases and air heated to reaction temperatures and capable of instituting an exothermic reaction in the presence of said material and thereby effecting dehydration and neutralization into the upper portion of said chamber, passing the reaction mixture in the direction of flow of said material for at least a portion of the length of said chamber. and subjecting the material in the lower portions of said chamber to heat exchange with a stream of cooling gas.

'7. A method of calcining raw catalytic material, which comprises subjecting it to `the heat given off by a chemical reaction that is set up within a moving stream of said material and controlling the temperature of calcination by heat exchange with the incoming reaction gas mixture.

8. A -method according to claim 7, in which` the temperature control is effected by passing the incoming reaction mixture first in indirect and then in direct heat exchanging relation with the descending catalytic material, the gas in direct heat exchanging relation being passed countercurrent to the flow f the catalytic material.

9. A process of calcining catalytic material, which comprises maintaining a continuous flow of said material, passing a mixture of gases through at least a portion of the ow of said catalytic material, said gases being capable of setting up an exothermic reaction in the presence of said catalytic material, and subjecting later portions of the flow of said material to the action of a cooling gas that is caused to pass in indirect heat exchanging relation with the material, to reverse its flow and pass in direct heat exchanging relation with the material and with the incoming gases, and to again reverse its flow and pass through the material in countercurrent to the flow thereof.

10. A method according to claim 1 in which the catalytic material is a pellet catalyst.

11. A method according to claim 7 in which the catalytic material'is an uncalcined pellet cat-v alyst. I

12. A method according to claim 1, in which the catalyst is a pellet contact sulfuric acid cat alyst.

13. A method according to claim 7, in which the catalyst is an uncalcined pellet contact sulfuric acid catalyst.

14. A method according to claim 1, in which the catalyst is a vanadium containing pellet catalyst for the contact sulfuric acid process.

l5. A method according to claim 7, inAwliich the catalyst is a vanadium containingiuncalcined pellet catalyst for the contact sulfuric acid process.

JOHANNES L. KOETZ. 

